Agriculture doesn't have the business certainty in this scheme that you're offering to other businesses. A farmer looking to get a million dollar loan doesn't know what will happen in three years' time do they?

PENNY WONG: Well we made a decision to exclude agriculture from the bill that's before the Parliament and we did that for a range of reasons and one of them is there's a lot of measurement, technical and other issues which we need to work through with farmers and with their representatives before that decision can be made.

LYNDAL CURTIS: If other countries keep agriculture out will Australia look to doing that as well?

PENNY WONG: Well I think that really does depend on where we get to. We said very clearly we're not going to include it in this bill. What we will include is a voluntary opt-in for land holders for forest establishment and we will allow that to occur in fact a year before the scheme starts, so there's a potential income stream for landholders who want to, on marginal land, establish forests.

LYNDAL CURTIS: The last major change to the economy the Goods and Services Tax wasn't voted on until all the details are clear. Yet you're asking the Senate to vote on a scheme where some of the details are far from clear aren't you?

PENNY WONG: Well look, can I say this; that in the GST and WorkChoices, both two very large, highly controversial pieces of legislation there were no regulations provided to the Senate before those votes were taken.

We've provided an unprecedented amount of material. We've provided activity statements which form the basis of regulations. We've done 18 months of work building on the work that was done by Prime Minister Howard's task group.

So we've had a green paper which was put out over a year ago which set out the Government's options; a white paper which the Prime Minister announced in December; draft legislation as well as draft regulations and activity statements for business which are the basis...

LYNDAL CURTIS: But the position...

PENNY WONG: So, so it is, we have provided an enormous amount of detail and those who are using this excuse are really I think finding another excuse to walk away from the national interest.

LYNDAL CURTIS: But the position of one of the major sectors, the coal industry isn't yet clear is it?

PENNY WONG: Well we have been clear that we will provide what we said which was $750 million to that sector. What we are working through and Mr Combet is engaged in those discussions is how that's best to be applied.

LYNDAL CURTIS: The certainty that there is, is that the vote today will be lost. The Opposition says it will produce amendments for negotiation that you've promised to do if they produce amendments. Are you willing to make any concessions in those negotiations?

PENNY WONG: Well what is certain today is that Labor senators will vote for the national interest. And what appears certain is that Opposition senators and the crossbenchers will not.

And I think it's important because today is in many ways, you know it's the big day; it's the day of reckoning on this issue. That this is a reform that is long overdue, that is in the national interest, that both major political parties said they would implement when they went to the last election.

And I can say Labor senators will be voting for this. The question will be; what will other senators do?

LYNDAL CURTIS: But it's not the final day...

PENNY WONG: Your question about negotiation, I just want to get to that. I think I've said not only on this program but on many media programs, when Mr Turnbull has serious and credible amendments that have the support of his party room I will sit down and discuss them with him.

LYNDAL CURTIS: And will you negotiate in good faith?

PENNY WONG: Not, not... Of course. I mean you don't sit in a room unless you're prepared to actually have an agreement. Not a single amendment has been put by the Liberal Party.

LYNDAL CURTIS: But Malcolm Turnbull made it clear on this program yesterday that he will be developing amendments and that he's prepared to negotiate. Without going into the details of what ground you may be prepared to give, are you prepared to give some?

PENNY WONG: I have already said I'd be prepared to negotiate amendments that are in the national interest, that are serious and credible and have the support of the party room. Not a single amendment has been forthcoming.